【单选题】如图所示,钢屋架上弦杆两节间在C、B点平面外有侧向支撑,两节间的轴向压力分别为N 4 和N 3 ,当计算CB杆(杆长l)平面外稳定时,其计算长度应为( )。
【简答题】如图所示,钢屋架上弦杆两节问在A、B点平面外有侧向支撑,两节间的轴向压力分别为N和2N,当计算AB杆平面外稳定时,其计算长度应为( )。 A.0.75(l 1 +l 2 ) B.1.25(l 1 +l 2 ) C.l 1 +l 2 D.0.875(l 1 +l 2 )
【单选题】屋架的受较大节间荷载作用的屋架上弦杆的合理截面形式是两个()。
【单选题】______ are those programs that help find the information you are trying to locate on the WWW.
【单选题】听力原文:W: What on earth are you doing here? M: I'm trying to fix the table. W: But the baby is sleeping. M: Why not take the baby to the next door where it's quiet? What does the man suggest?
A.
He suggests the baby be taken to the next room.
B.
He suggests the woman take the baby out of door.
C.
He suggests the woman be quiet.
D.
He suggests the woman shut the door.
【单选题】WHO, together with the medical workers in the different parts of the world, _____ trying to find a way to prevent the disease H1N1from _____. [ ]
【单选题】梯形屋架的端斜杆和受较大节间荷载作用的屋架上弦杆的合理截面形式是两个( )。
【单选题】钢屋架上弦杆两节间在A、B点平面外有侧向支撑,节间两杆件长度实际长度为l l 、l 2 ,
A.
的轴向压力分别为N和2N,当计算AB杆平面外稳定时,其计算长度应为: